What is the theme in Survivor by Chuck Palahniuk?

Sex and Power are themes in the novel. Throughout a large part of the book, Tender is completely obsessed with sex. This is because, as a tender in the Creedish Church, he was told he could never have sex or think about it. To deter children from having sex, the Church elders would force them to watch women giving birth. As the woman was having a child, the Church elders would scream at the children about how evil sex was and how horrible the consequences of having sex were. Naturally, seeing this happen time after time had ill effects on Tender.